Segment Information (Reportable Segment Information) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Sales to external customers	$ 294,733	$ 237,173	$ 571,232	$ 449,607
Intercompany sales
Net income attributable to Mine Safety Appliances Company	19,592	11,827	32,901	16,733
North America [Member]
Sales to external customers	137,691	116,774	268,607	215,888
Intercompany sales	25,917	20,767	50,460	38,672
Net income attributable to Mine Safety Appliances Company	16,111	12,928	25,934	18,512
Europe [Member]
Sales to external customers	74,868	56,406	139,707	113,030
Intercompany sales	30,311	20,890	58,698	43,666
Net income attributable to Mine Safety Appliances Company	2,094	(2,498)	3,681	(5,763)
International [Member]
Sales to external customers	82,174	63,993	162,918	120,689
Intercompany sales	4,359	4,122	8,017	7,470
Net income attributable to Mine Safety Appliances Company	6,466	3,549	13,843	7,927
Reconciling Items [Member]
Sales to external customers
Intercompany sales	(60,587)	(45,779)	(117,175)	(89,808)
Net income attributable to Mine Safety Appliances Company	$ (5,079)	$ (2,152)	$ (10,557)	$ (3,943)